Control electronics for a process device and method for operation therefor

Control electronics (E) according to the preceding claim,

• wherein the input circuit (ES) and the control unit (SE) are connected to each other via a digital data bus via which the control signal (CS) is transmitted.

Control electronics (E) according to any one of the preceding claims,

• wherein the control signal (CS) is a control command.

Control electronics (E) according to any one of the preceding claims,

• wherein the input circuit is a power module for supplying the control electronics (E), in particular the control unit (ES), with electrical energy, and/or a communication module for establishing communication of the control electronics (E), in particular the control unit (ES), via the two-wire loop (2L), preferably with a higher-level unit or another process device.

Control electronics (E) according to any one of the preceding claims,

• wherein the input circuit comprises an actuating element (SG) and a monitoring unit (PM), wherein the actuating element (SG) is used for setting the current and/or voltage in the two-wire loop (2L), wherein the monitoring unit (PM) is used for receiving the control signal (CS) from the control unit, and/or
• wherein the control unit (SE) is electrically connected at least intermittently, for example in the first operating mode, to the actuating element via the monitoring unit (PM).

Control electronics (E) according to any one of the preceding claims,

• wherein the operating mode of the input circuit (ES) is determined by the monitoring unit (PM).

Control electronics (E) according to any one of the preceding claims,

• wherein the input circuit (ES) is used to supply the control unit (SE) with electrical energy, in particular a supply voltage, preferably from the two-wire loop (2L).

Control electronics (E) according to any one of the preceding claims,

• wherein the operating mode of the input circuit (ES) is determined as a function of the control signal (CS) of the control unit (SE), in particular by means of the monitoring unit (PM).

Control electronics (E) according to any one of the preceding claims,

• wherein the operating mode of the input circuit (ES) is determined as a function of a value of the supply voltage of the control unit (SE), in particular by means of the monitoring unit (PM).

Control electronics (E) according to any one of the preceding claims,

• wherein the operating mode of the input circuit (ES) is determined as a function of the control signal (CS) of the control unit (ES) and as a function of a value of the supply voltage (V1, V2, V3) of the control unit (E), in particular by means of the monitoring unit (PM).

Control electronics (E) according to any one of the preceding claims,

• wherein the supply voltage (V1) has a first value between the actuating element and the monitoring unit.

Control electronics (E) according to any one of the preceding claims,

• wherein a shunt-block (SB), which is used to provide a supply voltage having a first value (V1), is provided between the actuating element (SG) and the monitoring unit (PM).

Control electronics (E) according to any one of the preceding claims,

• wherein the input circuit (ES) further comprises a voltage transformer (SW) which is used to convert the supply voltage received by the actuating element (SG) to a second value (V2).

Control electronics (E) according to any one of the preceding claims,

• wherein the control unit (SE) is electrically connected at least intermittently, preferably in the first operating mode, to the monitoring unit (PM) via the voltage transformer (SW).

Control electronics according to the preceding claim,

• wherein the input circuit (ES) further comprises a voltage regulator (SR), in particular a switching unit, which is used for controlling and/or for interrupting the voltage supply of the control unit (SR), in particular for interrupting the supply voltage with which the control unit (SR) is supplied with electrical energy.

Control electronics (E) according to any one of the preceding claims,

• wherein the supply voltage has a second value between the voltage transformer (SW) and the voltage regulator (SR).

Control electronics (E) according to any one of the preceding claims,

• wherein the control unit (SE) is electrically connected at least intermittently, preferably in the first operating mode, to the voltage transformer (SW) via the voltage regulator (SR), and is preferably electrically isolated from the voltage transformer (SW) during the second operating mode.

Control electronics (E) according to any one of the preceding claims,

• wherein the supply voltage has a third value (V3) between the voltage regulator (SR) and the control unit (SE).

Control electronics (E) according to any one of the preceding claims,

• wherein the monitoring unit (PM) is used to determine the first and/or the second operating mode, based on the first, second and/or third value of the supply voltage (V3).

Control electronics (E) according to any one of the preceding claims,

• wherein the current and/or voltage, which is taken from the two-wire loop or is adjusted in the two-wire loop (2L) by means of the actuating element (SG), is set by means of a signal (CS1), for example pulse-width modulated, which is predetermined by the monitoring circuit (PM), for example during both the first and also during the second operating mode.

Control electronics (E) according to any one of the preceding claims,

• wherein in the first operating mode a current value and/or a voltage value representing the control signal (CS) or the control command is set in the two-wire loop (2L) by means of the input circuit (ES), for example a PWM signal, particularly preferably by means of the monitoring unit (PM).

Control electronics (E) according to any one of the preceding claims,

• wherein in the second operating mode, a specified current value and/or voltage value stored in the input circuit (ES), preferably in the monitoring unit (PM), is set in the two-wire loop (2L), for example based on a PWM signal.

Control electronics (E) according to any one of the preceding claims,

• wherein the current value and/or voltage value transmitted, set or obtained in the second operating mode by the input circuit (ES), in particular by the monitoring unit, is an error signal or alarm signal.

Control electronics (E) according to any one of the preceding claims,

• wherein the current value and/or voltage value transmitted, set or obtained in the second operating mode by the input circuit (ES), in particular by the monitoring unit (PM), is a current value and/or a voltage value representing the control signal recently transmitted by the control unit (SE).

Control electronics (E) according to any one of the preceding claims,

• wherein in the second operating mode, a current and/or a voltage is set in the two-wire loop (2L) corresponding to the current and/or voltage value or the control signal which was set in a first operating mode that preferably immediately preceded the second operating mode.

Control electronics (E) according to any one of the preceding claims,

• wherein a first pick-up between the actuating element (SG) and the monitoring unit (PM) is used for picking up a first value of the supply voltage, and/or wherein a second pick-up between the voltage transformer (SW) and the voltage regulator (SR) is used for picking up a second value of the supply voltage, and/or
• wherein a third pick-up between the voltage regulator (SR) and the control unit (SE) is used for picking up a third value of the supply voltage.

Control electronics (E) according to any one of the preceding claims,

• wherein the actuating element (SG), the monitoring unit (PM), the voltage regulator (SR) and/or the voltage transformer (SW) are integrated at least partially, particularly preferably completely, in an ASIC (Application Specific Integrated Circuit) serving as an input circuit (ES).

Control electronics (E) according to any one of the preceding claims,

• wherein the voltage regulator (SR), which is preferably a switching unit that is used for interrupting the voltage supply to the control unit (SE), is activated by the monitoring unit (PM).

Control electronics (E) according to any one of the preceding claims,

• wherein in the event that one of the supply voltages exceeds or falls below a specified threshold value, the monitoring unit (PM) interrupts the voltage supply of the control unit (SE), in particular by means of the voltage regulator (SR), which is preferably a switching unit, and initiates the second operating mode.

Control electronics (E) according to any one of the preceding claims,

• wherein the control signal transmitted by the control unit (SE) is examined by means of the monitoring unit (PM) for errors, such as due to a fault,
• wherein in the event that the control signal transmitted by the control unit (SE) is faulty, the control unit (SE) is reset and/or the second operating mode is initiated.

Control electronics (E) according to any one of the preceding claims,

• wherein the second operating mode is maintained for a specified period of time by the monitoring unit, and/or
• wherein the second operating mode is maintained until the supply voltage exceeds or falls below a specified threshold value.

Control electronics (E) according to any one of the preceding claims,

• wherein in the second operating mode, the current value and/or the voltage value is set independently of the control unit (SE) or independently of the control signal (CS) of the control unit (SE) in the two-wire loop (2L) or is obtained from the two-wire loop (2L).

Control electronics (E) according to any one of the preceding claims,

• wherein the control unit (SE) is a unit for executing functions and/or functionalities of the process device, such as detecting at least one measured value and/or processing at least one measured value.

Control electronics (E) according to any one of the preceding claims,

• wherein the control signal further represents a communication signal to be transmitted via the two-wire loop (2L).

Control electronics (E) according to any one of the preceding claims,

• wherein during start-up or upon reboot of the process device, the input circuit (ES) is in the second operating mode or is operated in the second operating mode until the supply voltage, preferably between the input circuit and the control unit (SE) or between the voltage transformer (SW) and the voltage regulator (SR), has reached a specified threshold value for supplying the control unit (SE).

Control electronics (E) according to any one of the preceding claims,

• wherein after the supply voltage has reached the specified threshold value for operating the control unit (SE), the input circuit (ES) is operated in the first operating mode.

Control electronics (E) according to any one of the preceding claims,

• wherein the input circuit (ES), in particular the monitoring unit, comprises a buffer in which at least one control signal (CS) sent by the control unit (SE), or a value representing this control signal (CS), is stored.

Control electronics (E) according to any one of the preceding claims,

• wherein the monitoring circuit (PM) activates the actuating element (SG) in such a manner that a current value and/or a voltage value, which corresponds to the value present in the buffer, is set in the two-wire loop (2L).

Process device, in particular measuring device, of process automation technology having measurement and/or control electronics (E) according to any one of the preceding claims.

Method of operating a process device, wherein in a first operating mode, by means of a control signal transmitted by a control unit (SE), a current and/or voltage is set in the two-wire loop (2L) or is obtained from the two-wire loop (2L) by means of an input circuit,

• wherein, in a second operating mode, the current and/or the electric voltage is automatically set by means of the input circuit (ES) in the two-wire loop (2L) or is obtained from the two-wire loop (2L).

Method according to the preceding claim,

• wherein the current and/or voltage is set independently of the control unit (SE) or independently of a control signal possibly present in the input circuit (ES) by means of the input circuit (ES).

Computer program product with program code means which, when executed, are used for carrying out the method according to one of the preceding claims.

Use of the method and/or the measurement and/or control electronics (E) according to one of the preceding claims for operating a process device, in particular a measuring device.